2026-11-02
TTBy Tonetron Engineering Team · Dongguan Taitron Electronic Limited
Why does the same cable run at different speeds on different devices?
The link is negotiated to the lowest common capability, and long or marginal links can down-train.
Answer: a USB link runs at the lowest capability of the cable and both endpoints — and marginal links re-train downward.
- Capability mismatch — a 40 Gbps cable between a 40 Gbps host and a 10 Gbps device gives 10 Gbps.
- Signal margin — a long or damaged cable may negotiate lower to stay stable; this looks like "slower on this laptop".
- Port differences — ports on the same laptop are not always equal.
When a customer reports speed differences, record cable model, both endpoints and the negotiated rate before concluding.
Related questions
Browse HDMI and USB-C cables
Frequently asked questions
Why is the same cable faster on one device than another?
The link negotiates to the lowest capability of cable and both endpoints, and marginal links down-train.